39tii  Co-vukkss;  (        HOLSE  OF  REPRESENTATIVES.      (  Ex.  Doc 
2d  S ess  inv       t  '  \  No.  90. 


SURVEY  AT  HELL  GATE,  EAST  RIVER.  fNc/^ 

 i   /  %LilrO^ 

LETTEK 


FROM 


THE  SECRETARY  0E  WAR, 

TRANSMITTING 

A  report  of  the  survey  at  Hell  Gate,  Neiv  York. 


1  run  laky  14,  1S67. — Referred  to  the  Committee  on  Commerce  and  ordered  to  be  printed. 


War  Department. 
Washington  City,  February  11,  1S67. 
Sir  :  I  have  the  honor  to  transmit  herewith  a  communication  from  the  Chief 
of  Engineers,  of  February  9, 1867,  covering  a  report  by  General  Newton,  of  the 
corps  of  engineers,  on  the  survey  at  Hell  Gate,  New  York,  made  pursuant  to  the 
act  of  Congress  of  June  23,  1866. 

Very  respectfully,  sir,  your  obedient  servant, 

EDWIN  3VT.  STANTON, 

Secretary  of  War. 

Hon.  Schuyler  Colfax, 

Speaker  %f  the  House  of  Representatives. 


Engineer  Department, 

Washington,  February  9,  1867. 

Sir  :  In  obedience  to  the  provisions  of  the  act  approved  June  23,  1866, 
making  appropriations  for  the  repair,  preservation,  and  completion  of  certain 
public  works,  &c,  I  have  the  honor  to  transmit  herewith  a  copy  of  the  report 
of  Brevet  Major  General  John  Newton,  United  States  army,  lieutenant  colonel 
of  engineers,  on  the  survey  of  Hell  Gate,  New  York. 

General  Newton  submits  estimates  for  three  separate  projects  for  the  improve- 
ment, with  channels  of  twenty-six  and  twenty-four  feet  in  depth  at  mean  low 
water.  JThe  first  includes  the  removal  of  all  the  rocks  enumerated  in  his  report ; 
the  construction  of  sea-walls ;  improvement  of  the  middle  channel,  and  the  re- 
moval of  Negro  Head.  The  second  includes  the  cost  of  removing  that  part  of 
the  middle  reef  known  as  Negro  Head,  Hen  and  Chickens,  Flood  Rock,  and 
Gridiron,  thus  throwing  the  eastern  and  middle  channels  into  one.  The  third 
includes  the  removal  of  the  smaller  rocks  and  the  construction  of  the  sea-walls, 
but  makes  no  provision  for  improving  the  middle  channel,  or  otherwise  inter- 
fering with  the  middle  reef. 

The  third  project,  involving  the  least  expenditure  of  money  and  greatly 
ameliorating  the  danger  to  navigation,  essentially  that  recommended  by  the  ad- 
visory council  to  the  "  commissioners  relative  to  the  encroachments  and  preser- 


2  SURVEY  AT  HELL  GATE,  EAST  RIVER. 

vation  of  the  harbor  of  New  York,"  consisting  of  General  Totten,  chief  engineer 
United  States  army,  A.  D.  Bache,  superintendent  United  States  Coast  Survey, 
and  Commander  (now  Admiral)  Charles  Henry  Davis,  United  State-  navy, 
dated  September  ;J0,  1856,  is  recommended  as  the  best  to  be  undertaken  at 
present.  The  estimate  for  this  project,  giving  a  channel  of  twenty-six  feet  at 
mean  low  water,  is  *2, 877,000,  to  be  completed  in  four  years.  The  amount 
required  for  the  first  year's  operations,  including  purchase  of  machinery,  will  be 
8900,000.  The  entire  completion  of  the  improvement  to  be  undertaken  as  the 
demands  of  increasing  commerce  shall  warrant. 

General  Newton  enters  minutely  into  the  method  of  conducting  the  work,  the 
nature  of  the  requisite  machinery,  &c,  and  his  conclusions,  derived  from  a  close 
and  careful  study  of  the  questions  involved,  are  commended  to  the  attention  of 
the  War  Department. 

Very  respectfully,  your  obedient  servant, 

A.  A.  HUMPHREYS, 

Ch  ief  of  En  gin  errs. 

Hon.  Edwin  M.  Stanton, 

Secretary  of  War. 


United  States  Engineer  Office, 
lyo.  7  Boirfing  Green,  New  York,  January  21,  1S67. 

General  :  Having  been  assigned  by  department  letter  of  July  21,  1SG6,  to 
the  duty  of  examining  Hell  Gate,  and  having  been  further  instructed  by  letter 
of  July  25  to  make  such  examination  with  the  view  of  its  improvement  for  the 
purposes  of  navigation,  and  sufficiently  in  detail  to  present  a  plan  and  estimate 
for  the  necessary  operations,  I  have  the  honor  to  present  the  following  report : 

Lieutenant  Commanding  C.  H.  Davis,  assistant  in  the  coast  survey,  made  an 
examination  of  Hell  Gate,  and  a  report,  dated  February  15,  1S48.  He  states: 
"  Of  the  sailing  vessels  which  enter  Hell  Gate  passage,  it  is  estimated  that  one 
in  fifty  sustains  more  or  less  injury  by  being  forced  by  the  violence  of  the  cur- 
rents on  the  rocks  and  shoals.  *  *  *  The  damages  in 
this  channel  arise  from  the  great  strength  of" the  currents,  and  the  number  and 
positions  of  the  rocks  and  reefs.  The  strength  of  the  current  is  such,  that  sail- 
ing vessels  can  only  stem  its  force  or  escape  from  it  by  a  commanding  breeze  ; 
but  as  the  main  course  of  the  flood  tide  keeps  the  middle  of  the  easiern  chan- 
nel, it  is  most  secure  for  vessels  coming  from  the  westwarc^with  the  tide  to  place 
themselves  in  the.  middle  of  the  stream  and  follow  its  direction.  *  * 
This  plan,  however,  is  inadmissible  for  any  but  small  vessels,  on  account  of  two 
rocks,  the  Pot  and  the  Frying  Pan,  which  lie  in  or  very  near  the  mid-channel, 
and  in  the  way,  going  to  the  eastward  and  westward.  *  *  There 
is  a  reef  called  the  Way's  Reef,  which  lies  in  the  course  followed  by  steamboats 
principally,  when  coming  from  the  eastward  against  a  strong  flood.  It  is 
their  custom  to  keep  close  round  Fot  cove,  and  run  up  under  Hallet's  Toint, 
by  which  they  avoid  the  strength  of  the  flood.  In  this  part  they  find  an  eddy 
current  in  their  favor.  But  on  the  ebb,  the  greatest  danger  arises  from  the  di- 
vergence of  the  current  at  a  point  marked  A  on  the  sketch,  where  the  ebb  tide 
branches  off  into  three  directions,  to  take  the  course  of  the  three  channels,  and 
the  main  south  (ship?)  channel,  the  middle  channel,  and  the  eastern  channel. 
The  safe  navigation  depends  here  upon  deciding  sufficiently  soon,  at  the  point 
of  separation,  which  channel  shall  be  taken,  and  the  neglect  to  do  this,  or  a  loss 
of  control  over  the  vessel  for  any  reason,  frequently  results  in  being  carried  on  the 
Gridiron. 

"  When  a  vessel  that  has  attempted  the  eastern  channel  finds  herself  carried 
towards  the  Gridiron,  her  only  chance  for  safety  is  to  run  for  the  middle  chan- 
nel, which  is  narrow  and  made  precarious  by  the  m'ddle  reef,  the  outer  rock  of 


SURVEY   AT  HKLL  GaTE,   EAST  RIVER. 


3 


which  is  the  Xcgro  Head.  The  Gridiron  is,  owing  to  the  strong  set  of  the  tide 
on  it,  the  most  dangerous  reef  in  the  passage.  The  reef  known  as  the  Bread 
and  Cheese,  on  the  eastern  end  of  Blackwell's  island,  is  also  very  dangerous. 
Vessels  are  liable  to  go  on  it  in  the  flood,  when  it  is  covered,  by  getting  into 
the  eddy  near  it*  with  a  light;  wind.  The  chief  danger  is  on  the  ebb,  and  from 
the  same  cause  as  that  which  makes  Gridiron  dangerous,  that  is,  the  strong  set 
of  the  tide  in  that  direction."  Lieutenant  Commander  Davis  then  recommends 
the  removal  by  blasting  of  Pot  Rock,  the  Frying  Pan,  and  Way's  Reef,  and  also 
that  the  middle  reef  be  blasted  so  as  to  make  a  clear  channel  of  sufficient  depth 
for  common  vessels  and  steamboats  between  Flood  and  Little  Mill  rocks.  That 
piers  be  built  upon  Hog's  Back,  the  Gridiron,  and  Bread  and  Cheese,  of  stone, 
sufficiently  high  to  show  above  the  surface  of  the  water  at  least  four  t'eet ;  and 
that  these  piers  be  faced  with  wood,  and  provided  with  spring  fenders.  The 
piers  should  conform  to  the  natural  shape  of  the  reef. 

Bylander's  Reef,  by  the  same  report,  is  dangerously  situated  on  account  of 
the  deep  waters  around  it,  but  no  recommendation,  except  to  mark  its  position, 
is  made.  Lieutenant  Commanding  D.  D.  Porter,  United  States  navy,  under 
date  of  October  30,  1S48,  reports  in  favor  of  the  plan  of  improvement  of  Lieu- 
tenant Davis,  except  the  blasting  of  the  middle  channel  reef,  which  is  too  diffi- 
cult, and  suggests  it  be  entirely  filled  in  with  docks,  provided  with  spring  fenders. 

He  recommends,  likewise,  the  removal  of  certain  small  rocks  not  before 
mentioned:  Bald-headed  Billy,  a  rock  opposite  Gibbs's  Point,  and  within  fifty 
yards  of  Blackwell's  island;  a  small  and  dangerous  rock  southward  of  Wool- 
sey's  bath-house  ;  Scaley  Rock,  and  close  to  it  Shell  Rock. 

Hallet's  Point,  he  states,  should  by  all  meaus  be  removed.  "  At  tide  it  causes 
the  eddies  in  Pot  cove,  and  on  the  ebb  tide  the  eddies  in  east  channel  "  *  * 
Towards  the  close  of  his  report,  "  No  one  can  form  an  idea  of  the  number  of 
vessels  that  go  on  shore  during  the  course  of  a  month.  Fifty  went  on  shore 
during  the  period  I  was  occupied  there,  (two  months,)  and  many  of  them  were 
much  injured." 

He  suggests,  likewise,  "  A  close  examination  of  the  shore  at  low  water. 
Many  rocks  will  be  found  to  exist  of  a  dangerous  character,  and  they  have  at 
different  times  clone  much  damage  to  vessels  of  a  lighter  draught." 

Operations  at  Hell  Gate  to  improve,  the  navigation  by  blasting  rocks,  from 
August,  1851,  to  Recembcr,  1853,  under  the  superintendence  of  the  late  E. 
Merriam,  esq.,  and  subsequently  of  the  late  Major  Fraser,  corps  of  engineers. 

Mr.  Merriam,  in  his  letter  of  the  22d  of  December,  1852,  to  General  Totten, 
chief  engineer  United  States  army,  states :  "When  M.  Maillefert  commenced 
tiring  on  Pot  Rock,  the  19th  August,  1851,  there  was  but  eight  feet  of  water 
upon  it.  On  the  3d  of  September,  Lieutenant  Bartlett  made  an  examination  of 
that  rock,  by  which  it  appeared  that  the  rock  had  been  reduced  four  and  a  half 
feet  by  sixteen  charges.  On  the  18th  October,  Lieutenant  Bartlett  addressed 
a  letter,  the  original  draught  of  which  was  by  him  (i.  e.  Maillefert)  handed  over 
to  me,  in  which  he  stated  that  M.  Maillefert  had  reduced  Pot  Rock  to  sixteen 
feet,  mean  low  water.  At  that  date  M.  Maillefert  had  fired  eighty-five  charges 
on  Pot  Rock. 

"  On  the  2d  and  3d  of  January,  1852,  he  (i.  e.  Lieutenant  Bartlett)  again  sur- 
\  yed  Pot  Rock,  and  stated  (officially)  that  there  was  nineteen  feet  of  water  on 
Pot  Rock.  Up  to  that  date  two  hundred  and  thirty-four  charges  had  been  fired 
on  that  rock.  On  the  27th  March,  1852,  Lieutenant  Bartlett  addressed  to  me  a 
letter  from  Washington,  in  which  he  stated  that  he  had  made  a  survey  of  Pot 
Rock  on  the  15th  of  that  month,  and  found  net  less  than  twenty  and  a  half  feet 
of  water  upon  it  at  the  shoalest  part;  and  that  it  had  been  reduced  from  two 
hundred  and  twenty-five  feet  length,  to  one  hundred  r,nd  seventy- two  feet  length, 
and  from  sixty  feet  width  to  forty  feet  width. 


4 


SURVEY  AT  HELL  GATE,   EAST  RIVER. 


"  From  the  recommencement  of  operations  in  February  to  the  date  of  this  sur- 
vey there  had  been  fifty  charges  fired  on  Pot  Rock,  making  two  hundred  and 
eighty-four  charges  from  the  commencement. 

"  It  seemed  reasonable  to  suppose,  if  the  water  on  Pot  Rock  had  been  increased 
from  eight  to  twenty  and  a  half  feet,  and  the  length  reduced  from  two  hundred 
and  twenty-five  to  one  hundred  and  seventy-two  feet,  and  its  width  reduced 
from  sixty  to  forty  feet,  by  two  hundred  and  eighty -four  charges,  that  two  hun- 
dred additional  charges  would  complete  -its  reduction  to  the  depth  of  twenty- 
four  feet;  hence  my  estimate  of  September  17,  1852." 

Mr.  Merriam,  in  his  statement  of  operations  on  the  rocks  of  Hell  Gate 
and  East  river,  submitted  to  the  Committee  on  Naval  Affairs  of  the  United 
States  Senate,  August,  1£52,  gives  the  following : 

RECAPITULATION. 


Name. 

Charges. 

Pounds  of 
powder. 

Cost. 

Rock  removed. 

Pot  Rock  

Frying-  Pan  

Way's  Reef  

Shelldrake  

Bald-headed  Billy  

Hoyt's  Rocks  

Diamond  Reef  

Hallet's  Point  

Total  .  

284 
105 
135 
0 
1 
8 
78 
3 

34, 231 
12, 387 
15,549 
750 
•  ]25 
1,000 
9,750 
400 

$6,837  30 
2,116  81 
2, 543  66 
110  34 
500  00 
250  00 
1,434  42 
69  06 

m  feet. 

94  feet. 

9l  feet. 

8£  feet. 
Entirely. 
Entirely. 

2  feet. 
No  result. 

620 

74, 192 

13,861  59 

In  the  same  paper  he  gives  the  following  record  of  the  depth  of  water  upon 
the  rock,  prior  to  the  commencement  of  his  operations,  and  at  the  close  tnereof : 


Name. 


Pot  Rock  

Frying  Pan. . . 
Way's  Reef... 

Shelldrake  

Diamond  Reef 


Original 
depth. 

Depth  at  close 
of  operations. 

8  feet. 

20i  feet. 

9  feet. 

18*  feet. 

#  5  feet. 

IU  feet. 

8  feet. 

16*  feet. 

16  feet. 

18  feet. 

This  reported  increase  of  depth,  due  to  blasting,  will  be  found  exaggerated, 
though  without  fault  of  Mr.  Merriam,  who  was  deceived  by  the  official  reports 
of  the  surveys.  He  is,  on  the  contrary,  entitled  to  great  credit  for  the  results 
actually  attained,  and  for  the  arduous  and  efficieut  services  which  he  gratuitously 
rendered  to  further  an  important  public  improvement. 

Congress  in  1S52  having  made  an  appropriation  of  $20,000  for  the  removal 
of  rocks  at  Hell  Gate,  this  operation  fell  under  the  charge  of  the  engineer 
department,  and  Major  Fraser,  corps  of  engineers,  was  assigned  to  the  duty. 
Major  Fraser  presented  his  preliminary  estimates,  based  upon  the  depths  given 
above.  But  immediately  after  having  surveyed  Pot  Rock,-  he  reports,  October 
22,  that  instead  of  there  being  twenty  and  one-half  feet,  there  was  actually  but 
a  little  over  eighteen  feet  of  water  upon  the  rock.  This  discovery  showed  a 
much  diminished  quantity  of  work  done,  and  indicated  a  large  increase  of  his 
previous  estimate. 

He  recommended  the  removal  of  the  following  rocks  :  Pot  Rock,  Frying  Pan, 
Way's  Reef,  the  rock  near  Woolsey's  bath-house,  certain  loose  rocks  near  the 
shore,  a  part  of  Hallet's  Point,  and  certain  sharp  points  at  Negro  Head,  in  the 


SURVEY  AT  HELL  GATE,  EAST  RIVER. 


5 


middle  channel.  On  November  10, 1S52,  Major  Eraser  reports  Pot  Rock  to  be, 
at  the  twenty-four-foot  curve,  two  hundred  and  twenty  feet  in  length  andsixtv- 
three  feet  across  at  the  widest  part. 

His  survey  of  June  28  and  29,  18o3,  shows  a  minimum  depth  on  the  rock 
of  twenty-one  feet  four  inches,  at  low  water,  as  the  result  of  firing  eight  hun- 
dred charges  at  a  cost  of  $14,963  O'J.  It  is  quite  likely  that  one  hundred  charges 
were  subsequently  fired,  though  no  certain  record  can  be  found,  and  that 
-SIS, 000  nearly  was  devoted  to  blasting  on  Pot  Hock. 

.  In  July,  1S53,  Mr.  Fraser  estimated  the  cost  of  removal  of  one  cubic  foot  of 
rock  at  SI  14 

Several  of  his  reports  during  the  fall  of  1853,  and  the  sketch  of  his  survey 
in  October  of  that  year,  appear  to  have  been  lost. 

The  method  pursued  under  the  superintendence  of  Mr.  Merriam  and  of  Major 
Fraser  excluded  the  employment  of  diving-bells  or  .submarine  armor,  and  the 
charges  of  powder  were  consequently  placed  in  position  without  that  examina- 
tion of  the  bottom  which  would  have  developed  in  each  charge  its  full  useful 
effect. 

The  work  was  finally  suspended  for  want  of  funds,  and  since  1S52  no  appro- 
priation has  been  made  by  Congress  for  the  removal  of  these  obstructions. 

The  advisory  council  to  the  "  commissioners  relative  to  the  encroachments 
and  preservation  of  the  harbor  of  New  York,"  consisting  of  General  Totten, 
chief  engineer  United  States  army;  A.  D.  Bache,  superintendent  United  States 
Coast  Survey,  and  Commander  Charles  Henry  Davis,  United  States  navy,  made 
to  that  body,  September  30,  1S56,  an  important  report  upon  the  improvement 
of  the  navigation  of  Hell  Gate  passage,  which  is  to  be  found  on  page  197  of  the 
Reports  of  the  New  York  Harbor  Commission  of  1857,  republished  by  order  of 
the  Chamber  of  Commerce. 

A  thorough  survey  of  this  channel  was  made  by  Lieutenant  Commanding 
Craven,  assistant,  Coast  Survey,  and  a  current-chart  prepared  to  illustrate  their 
report. 

The  advisory  council  recommends  the  removal,  by  blasting,  of  Pot  Rock,  Fry- 
ing Pan,  Way's  ^feef,  a  portion  of  Hallet's  Point,  and  other  rocks  of  minor  conse- 
quence, Bald-headed  Billy,  Blackwell's  Rock,  a  rock  near  Negro  Point,  two  east 
of  Woolsey's  bath-house,  and  one  to  the  southward  of  that  building. 

The  council  likewise  recommends  the  closing  of  the  small  channel  between 
the  Bread  and  Cheese  and  the  head  of  Blackwell's  island;  the  building  of  stone 
piers,  with  spring  fenders,  on  Hog's  Back,  the  Gridiron,  and  Bread  and  Cheese, 
and  the  erection  of  a  beacon  on  Rylander's  Reef. 

The  report  of  Lieutenants  Commanding  C.  H.  Davis  and  D.  D.  Porter,  and 
of  the  advisory  council,  together  with  the  notes  and  extracts  taken  therefrom, 
furnish  a  full  catalogue  of  the  dangers  and  obstructions  to  this  navigation,  and 
it  is  not  thought  necessary  to  dwell  longer  upon  this  branch  of  the  subject. 

During  the  present  season  surveys  and  examinations  of  Hallet's  Point,  Scaly 
Rock,  the  Frying  Pan,  and  Pot  Rock  have  been  made,  and  the  results  given  in 
the  sketches  herewith. 

An  examination  was  likewise  made  by  divers  of  the  surfaces  of  Pot  Rock  and 
Frying  Pan,  principally  with  the  view  of  ascertaining  the  feasibility  of  blasting 
by  placing  the  charges  upon  the  rock,  and  although  nothing  special  has  been 
elicited  the  indications  are  that  some  of  the  blasting  necessary  to  be  done  can 
be  effected  by  simply  placing  the  charge  in  contact  with  the  rock. 

WORK  PROJECTED  FOR  THE  IMPROVEMENT  OF  THE   CHANNEL  OK   HELL  (.ATE. 

This  portion  of  the  subject  has  so  frequently  been  di-cussed  by  officers  of 
distinguished  ability,  whose  reports  are  published,  that  little  further  remains  to 
be  said.    It  is  agreed  that  certain  rocks  in  the  channel,  viz.,  Pot  Rock,  Frying 


6 


SURVEY  AT  HELL  GATE,  EAST  RIVER . 


Pan,  "Way's  Reef,  Shelldrake,  and  others  nearer  shore,  viz.,  the  rock  of  Negro 
Point,- those  near  Woolsey's  bath-house,  Blackwell's  Rock,  together  with  por- 
tions of  Hallet's  Point  and  of  Scaly  Rock,  should  be  removed.  Sea-walls  have 
been  likewise  recommended  to  be  built  on  the  Gridiron,  Hog's  Back,  and  on  the 
Bread  and  Cheese,  and  a  stone  beacon  to  be  placed  on  Rylander's  reef. 

To  the  rocks  to  be  removed  may  be  added  the  Heeltap  Rocks,  situated  off  the 
end  of  Great  Mill  Rocks,  which,  by  their  position,  compel  vessels  to  make  such 
a  circuit  as  to  endanger  their  safe  passage  past  Rylander's  Reef.  To  the  sea- 
walls may  be  added  one  upon  Rylander's  reef  and  another  along  the  seventeen- 
foot  curve  of  Great  Mill  Rock,  on  the  side  of  the  middle  channel,  to  mark  the 
passage  and  to  sheer  off  vessels. 

The  great  reefs  in  the  middle  of  pass — Flood  Rock,  Negro  Head,  the  Giidiron, 
and  Great  and  Little  Mill  Rocks — have  been  little  noticed  in  any  scheme  of  im- 
provement, notwithstanding  they  form  the  greatest  obstacle  to  the  pass  of  Hell 
Gate  being  converted  into  a  highway  for  commerce.  In  the  existing  state  of  the 
art  of  removing  rock  under  water,  the  imagination  was  appalled  at  the  notion 
even  of  meddling  with  such  means. 

The  middle  channel  is  narrow  and  is  rendered  dangerous  by  the  projection 
of  Nego  Head  into  its  lower  outlet.  The  least  improvement  that  can  be  recom- 
mended in  this  report  should  include  Negro  Head,  and  the  increase  of  the  width 
of  this  channel  to  about  three  hundred  and  forty  feel,  as  marked  on  the  map  sent 
herewith. 

Estimates  arc  submitted  for  three  projects. 

The  first  includes  the  removal  of  all  rocks  mentioned  at  the  beginning  of  this 
division  of  the  report,  with  the  construction  of  the  sea-walls,  and  likewise  pro- 
vides for  the  improvement  of  the  middle  channel  and  the  removal  of  Negro 
Head. 

The  second  includes  the  cost  likewise  of  the  removal  of  that  part  of  the  mid- 
dle reef  known  as  Negro  Head,  Hen  and  Chicken,  Plood  Rock,  and  Gridiron, 
thus  throwing  the  eastern  and  middle  channels  into  one. 

The  third  includes  the  smaller  rocks  and  the  sea-walls,  and  makes  no  provision 
for  improving  the  middle  channel,  or  otherwise  interfering  with  the  middle  reef. 
With  every  improvement  of  Hell  Gate,  the  number  of  vessels  passing  through 
will  increase  and  the  necessity  for  further  room  will  become  more  apparent. 
Hell  Gate  now  washes  with  its  waters  the  corporate  limits  of  the  city;  before 
many  years  it  will  form  a  portion  of  the  busy  harbor  of  New  York,  and  then 
will  there  arise  a  demand  for  improvement  to  an  extent  which  has  not  yet  in 
idea  even  been  entertained.  The  uncertainty  and  slowness  attending 'blasting 
under  water  has  had  the  effect  of  diverting  public  attention  from  that  considera- 
tion of  Hell  Gate  to  which  the  importance  of  the  improvement  is  really  entitled, 
and  it  is  believed,  as  soon  as  the  work  can  be  pushed  in  a  regular  manner, 
subject  to  fixed  laws  of  calculation,  like  blasting  on  land,  that  the  extent  of 
improvement  needed  for  the  interests  of  commerce  will  be  the  sole  limit  to  public 
effort  in  this  direction. 

What  extent  of  work  is  really  demanded  now  for  the  future  is  a  problem  which 
more  properly  belongs  for  solution  to  those  representing  the  interests  of  com- 
merce in  this  city,  owing  to  their  more  perfect  acquaintance  with  its  wants  and 
capacity.  This  report  does  not  prescribe  these  limits,  but  the  estimates,  tables, 
and  other  information  here  furnished  will  enable  any  one  to  calculate  the  expense 
of  projects  different  from  those  formally  set  forth. 

Estimates  for  twenty-four  and  twenty-six  feet  depth  at  mean  low  water  are 
separately  made  on  each  project. 

To  W.  S.  Edwards,  esq.,  assistant  in  the  Coast  Survey,  1  am  indebted  for  sur- 
veys of  Pot  Rock,  Prying  Pan,  and  the  Heeltap  Rocks,  made  under  circum- 
stances of  difficulty  ;  and  to  G.  W.  Blunt,  commissioner  of  pilotage,  for  reliable 
information  in  this  and  other  cases  for  the  benefit  of  the  harbor. 


SURVEY   AT   HELL  GATE,   EAST  RIVER. 


7 


MODE  OF  CONDUCTING  OPERATIONS. 

Tin;  quantity  of  work  to  be  done  and  the  consequent  eost,  as  .shown  in  the 
estimates,  are  bo  great  as  to  demand,  before  embarking  largely  into  it,  that  a 
project  for  the  operations,  not  only  reasonable  in  itself,  but  subjected  to  fixed 
laws  of  calculations,  should  be  presented;  but,  before  entering  upon  this  subject, 
it  would  be  well  to  discuss  the  process  already  employed,  and  ascertain,  if  possi- 
ble, what  the  results  have  been. 

The  improvements  at  Hell  Gate  were  made  by  exploding  charges  ol  powder 
placed  upon  the  rock,  no  advantage  being  taken  of  submarine  apparatus  of  any 
kind  to  establish  these  charges  where  the  greatest  effects  might  result.  So  long 
as  the  rock  was  found  in  isolated  or  separate  pinnacles,  this  process,  imperfect  as 
it  was,  produced  great  effects.  But  when  the  projecting  points  were  knocked 
away,  and  the  solid  bed  of  rock  reached,  progress  became  slow  and  doubtful, 
and  the  cost  great.  The  small  amount  of  appropriation  granted  by  Congress 
having  been  exhausted,  the  work  has  since  been  left  in  this  unsatisfactory  state. 

The  rock  blasted  was  supposed  to  have  been  blown  into  deep  water  by  the 
force  of  the  charge,  since  there  was  no  provision  made  tor  its  removal  by  other 
means,  but  it  is  evident  that  such  results  became  very  problematical  when 
the  area  of  the  rock  is  increased  and  the  distance  to  which  the  fragments  should 
be  moved  increased. 

Xo  reliable  estimate  could  be  framed  upon  such  a  process,  even  if  it  were 
sure  to  be  attended  with  final  success,  which  is  more  than  doubtful. 

The  employment  of  divers,  which  the  small  amount  appropriated  for  this  im- 
provement did  not  justify,  would  have  had  a  result  more  satisfactory,  and  perhaps 
have  furnished  data  for  calculation.  As  it  is,  for  this  particular  locality  no  ad- 
ditions to  our  previous  knowledge  have  been  gained.  The  project  presented  in 
this  report  consists  in  first  preparing  the  surface  for  ulterior  operations  by 
blowing  off  the  sharp  points  and  projections,  by  charges  placed  in  position  by 
divers,  until  the  rock  is  reduced  to  a  more  uniform  surface,  then  to  blast  the 
rock  by  introducing  charges  into  drill-holes  made  for  the  purpose,  and  to  re- 
move the  debris  by  divers. 

The  current,  which  has  a  maximum  velocity  of  S  .30  miles,  limits  the  time  of 
working  under  water  to  a  little  over  two  hours  per  day,  during  and  about  the 
time  of  slack  water ;  and  hence  the  time  and  expense,  unless  some  means  of 
shielding  the  divers  and  operators  from  the  force  of  the  current  can  be  devised, 
would  prove  a  serious  objection. 

Even  if  the  persons  using  the  drill  were  protected  from  the  current,  the  de- 
lay incident  to  this  mode  of  operations  would  be  considerable  ;  but  if  the  drill-* 
ing  were  conducted  from  the  surface  of  a  platform  above  the  water,  the  same 
results  would  be  reached  as  on  dry  land. 

A  platform  of  suitable  size,  with  vertical  sliding  supports,  capable  of  being 
raised  or  lowered  through  a  convenient  height,  is  prepared  and  floated  to  its 
position,  supported  on  the  decks  of  two  scows  or  other  floats,  one  on  each  side. 
Arrived  at  the  place,  the  floats  are  moored,  the  vertical  supports  of  the  plat- 
form let  down  to  the  bottom,  securely  fastened  to  the  platform,  and  braced  to 
each  other  if  necessary.  This  operation  being  done  at  the  top  of  the  tide,  the 
SCOWS  are  floated  away,  when  the  water  falls.  The  supports  to  the  platform 
may  be  placed  within  ten  feet  of  each  other,  and  the  weight  of  the  platform,  to 
insure  steadiness  and  stability,  fixed  at  any  desirable  standard. 

The  supports  may  be  lashed  above  and  below  the  platform  to  the  uprights 
placed  for  that  purpose,  and  may  be  wedged  also  to  prevent  working. 

To  avoid  the  interference  of  the  currents  with  the  drills,  these  may  be  made 
to  work  in  hollow  iron  cylinders,  reaching  from  the  platform  to  the  rock. 

A  steam  engine  or  machine  worked  by  hand  can  then  be  applied  to  the  drills 
and  the  work  pushed  regardless  of  the  currents. 


8 


SURVEY  AT  HELL  GATE,  EAST  RIVER. 


To  remove  the  rock  blasted,  it  will  likewise  be  necessary  to  protect  the  per- 
sons of  tlie  divers  from  the  force  of  the  currents,  and  it  is  proposed  to  do  this 
in  the  following  or  similar  mode  : 

Two  cylindrical  floats,  of  sufficient  bouyancy,  made  of  boiler  iron,  are  placed 
say  thirty  feet  from  centre  to  centre.  Towards  their  extremities  they  are  in- 
clined towards  each  other  until  they  meet,  forming  one  float,  say  one  hundred 
and  sixty  feet  long  and  forty  wide.  Curtains  of  iron,  extending  along  the  whole 
outer  line  of  the  floats,  are  permanently  fastened  at  their  upper  lines  to  these 
floats,  the  lower  end  of  the  curtain  being  attached  by  falls  to  davits  or  small 
derricks  upon  the  floats,  so  as  to  be  lowered  or  raised  at  will.  These  curtains 
are  separated  into  lengths  of  about  twenty  feet,  that  each  may  be  managed  in- 
dependently of  the  other. 

The  curtains  should  be  flexible,  and  may  be  made  of  plates  of  iron  say  one 
foot  wide  and  twenty  long,  connected  with  those  in  contact  by  hinge  joints. 

The  floats  being  placed  in  position  and  moored  securely,  the  curtains;  by  sec- 
tions, are  let  down  to  the  bottom,  their  extra  depth  allowing  an  extent  of  several 
plates  to  rest  upon  the  rock. 

An  interior  space  of  160  feet  by  40  on  the  bottom  is  thus  protected,  where  the 
divers  can  fill  the  buckets,  whioh  are  afterwards  raised  and  emptied  into  scows, 
with  valve  bottoms,  lying  alongside.  The  debris  is  then  towed  away  and  de- 
posited where  desirable. 

There  is  nothing  in  these  expedients  which  suggest  practical  difficulties  which 
skill  could  not  surmount,  and  confidence  is  felt  that  these  or  similar  contrivances 
can  be  relied  upon  to  solve  this  problem.  Before  work  is  really  undertaken 
trials  should  be  made  and  prosecuted  until  a  good  result  is  obtained. 

There  is  no  doubt  felt  that  the  obstacle  in  the  way,  viz.,  the  force  of  the  cur- 
rent, can  be  neutralized,  and  it  remains  only  to  decide  whether  the  object  is 
worth  the  money  it  will  cost,  a  question  which  it  is  the  privilege  of  others  to  de- 
termine. 

DATA  FOR  THE  ESTIMATE. 

The  rock  in  the  samples  obtained  contains  an  excess  of  mica,  making  it  soft 
to  the  drill.  The  drill  is  supposed  to  bore  seven  feet  a  day,  though  it  may  av- 
erage ten  feet.  The  estimated  cost  of  drilling  includes  mooring  and  arranging 
the  platform,  services  of  men  attending,  of  blacksmiths  sharpening  tools,  steel 
expended,  services  of  engineer  and  firemen,  coal  used  in  the  smithery  and  for 
the  engine,  services  of  divers,  in  arranging  the  supports  of  the  platform  and 
placing  the  drilling  tubes,  labor  of  unmooring  platform,  &c.  Estimated  cost 
j)cr  lineal  foot,  $4. 

The  cost  of  each  charge  includes  the  estimated  cost  of  drilling  the  rock,  of 
the  canister  and  charge,  labor  of  divers  in  placing  the  charge,  services  of  the 
operator  and  boat's  crew  in  firing,  expense  of  wires,  &c.  The  small  charges 
are  first  placed  in  the  holes  and  split  up  the  rock  ;  the  larger  charges  are  intro- 
duced into  the  crevices  and  seams  thus  formed,  and  complete  the  work  of  break- 
ing up  the  mass. 

Estimate  for    50    pound  charge  of  gunpowder,  $45  50,  drilling  included. 
150  .'"  "  41  75. 

5  "  nitro-glycerine,    43  64,  drilling  included. 

15  "  m  35  35. 

S\\  "  "  41  63,  drilling  included. 

11TV         "  "  29  29. 

The  sea-wall  on  the  Gridiron  is  intended  to  be  of  large  cut  blocks,  regularly 
coursed.  The  top  is  to  be  4  feet  above  highest  water.  The  general  height  is 
23  feet,  at  certain  points  28  feet,  and  its  thickness  is  ten  feet.    Some  of  the  rock 


SURVEY  AT  HELL  GATE,  EAST  RIVER. 


9 


taken  from  the  channel  should  be  deposited  behind  the  wall  to  the  level  of  low 
water,  to  form  a  backing.  This  can  be  done  without  extra  expense.  The  por- 
tion of  wall  to  be  laid  under  water  is  first  enclosed  by  a  coffer-work  of  wood, 
not  water-tight,  intended' solely  to  protect  the  divers  from  the  force  of  the  cur- 
rent. This  expense  is  included  in  the  estimate,  as  well  as  that  of  forming  a  bed 
for  the  foundation.  The  supposed  cost  will  be  $80  per  cubic  yard.  The  expense 
of  this  construction  should  limit  its  employment  to  the  most  important  cases. 

The  rubble  sea-walls  are  composed  of  stone  thrown  in  loosely  to  the  level  of 
low  water,  but  above  that  to  the  top,  4  feet  above  highest  water,  a  dry  wall  of 
split  uncut  blocks  is  supposed  to  be  laid  by  hand.  The  loose  rubble  foundation 
is  12  feet  wide  at  the  top,  and  the  slope  to  the  bottom  is  supposed  to  be  one  to 
one  and  a  half  or  two.  The  superstructure  is  10  feet  thick  and  11  feet  high. 
The  estimated  cost  is  $4  50  per  cubic  yard  for  the  rubble,  and  $24  for  the 
superstructure. 

A  large  estimate  is  necessary  for  machinery,  including  scows,  boats,  anchors, 
chains,  cordage,  and  liberal  allowance  for  losses,  wear  and  tear,  arising  from  the 
peculiar  nature  of  the  service  required.  Accidents  from  collisions,  and  conse- 
quent repairs,  incident  to  the  strong  currents  and  the  number  of  passing  vessels, 
will  probably  be  frequent,  and  should  be  kept  in  view.  In  this  estimate  every 
machine,  scow,  or  boat  is  intended  for  a  clearly  defined  service. 

The  cost  from  this  estimate  of  blasting  and  removing  each  cubic  foot  of  rock 
is  $1  64.  Major  Fraser  in  1853,  from  the  results  of  the  process  of  removal  used 
by  him,  found  the  cost  then  to  be  $1  14  per  foot,  which  at  present  rates  would 
be  at  least  SI  71.  But  Major  Fraser  expended  nothing  for  removing  the  rock 
by  hand,  the  charge  of  powder  being  supposed  to  do  that.  The  estimate  is 
therefore  not  in  excess,  and  is  kept  to  this  low  limit  by  the  contemplated  use  of 
the  proper  machinery. 

Table. 


To  a  depth  of  26    To  a  depth  of  24 
Subject.  ft.  at  mean  Ioav      ft.  at  mean  low 

water.  water. 


Estimated  cost  of  first  project   s5,  723. 129  15       $5,  008  579  95 

Amount  saved  by  using  drill,  boring  into  rock  at  the 
rate  of  one  inch  per  minute,  including  cost  of  one 

drilling  platform,  which  might .then  be  dispensed  with.  51,014  00              48,530  00 

or  less  than  one  per  cent. 

Amount  saved  by  using  nitro-glycerine,  instead  of  gun- 
powder, when  its  explosive  force  is  estimated  at  ten 

times  that  of  the  latter    76,430  B0             65,502  00 


Amount  sated  by  using  nitro-gly  -'eriue,  instead  of  gun- 
powder, when  its  explosive  force  is  estimated  at 

thirteen  times  that  of  the  latter   141,745  37  122,  075  30 


or  T]3o  per  cent. 

45  37  ]  12 
or  less  than  2|  per  cent. 


The  small  proportion  which  an  improved  process  of  drilling  the  rock,  or  the 
use  of  a  more  powerful  explosive  agent,  will  save  in  the  total  cost,  may  surprise 
mauy ;  but  the  cause  is  evident,  viz.,  the  small  proportion  of  the  cost  of  the 
whole  blasting  process  +o  that  of  the  other  items  of  the  project. 

The  table  likewise  shows  that  as  a  question  of  cost  this  improvement  is  inde- 
pendent of  any  particular  form  of  improved  machinery  for  drilling,  or  special 
explosive  agent,  leaving  to  the  government  full  liberty  of  choice  in  these  re- 
spects.   For  the  sake  of  the  men  employed  upon  such  works  no  compound 


10 


SURVEY  AT  HELL  GATE,  EAST  RIVER. 


should  be  used  which  is  liable  to  explode  spontaneously,  or  from  causes  beyond 
the  control  of  ordinary  carefulness. 

Certain  conclusions  may  here  be  concisely  stated : 

1.  Any  reasonable  hope  of  effecting  this  improvement  depends  upon  the  re- 
jection of  misty  and  fanciful  schemes,  which  cannot  be  brought  within  the  rules 
of  ordinary  calculation.  This  report  has  attempted  one  method  of  solution,  and 
it  is  hoped  many  better  may  be  found. 

2.  It  was  necessary  in  framing  the  estimate  to  make  just  and  liberal  allow- 
ances, and  to  provide  for  contingencies  and  accidents  attending  operations,  not 
only  difficult  in  themselves,  but  also  little  assisted  by  data  derived  from  any 
source.  On  the  other  hand,  there  is  no  doubt  that  a  serious  and  well-considered 
attempt  to  push  the  work  will  be  the  means  of  stimulating  mechanical  inven- 
tions suited  to  this  end,  which,  with  the  experience  gained  from  day  to  day,  will 
not  only  expedite  the  progress,  but  also  materially  diminish  the  cost,  especially 
in  the  large  item  of  removing  the  rock. 

3.  The  precise  depth  to  be  attained  will  be  dependent  not  only  upon  the 
present,  but  upon  the  future  draught  of  vessels.  On  this  point,  it  must  be  con- 
sidered that  this  is  the  only  channel  leading  to  New  York  where  additional 
depth  could  be  gained  ;  and  a  liberal  standard  in  fixing  this  would  be  best,  since 
if  error  be  committed  in  the  opposite  extreme,  the  cost  of  remedy  would  nearly, 
if  not  quite,  equal  that  of  the  first  operation. 

4.  A  resurvey  of  the  rocks  obstructing  the  passage,  to  iix  their  precise  out- 
lines, is  very  necessary.  The  Coast  Survey  office  intend  to  begin  this,  it  is  un- 
derstood, in  the  spring.  *A  marked  difference  in  the  character  of  Prying  Pan 
and  the  Heeltap  Rocks  may  be  seen  by  comparing  the  general  map  sent  here- 
with with  the  last  partial  surveys  of  Mr.  W.  8.  Edwards,  assistant  Coast  Survey. 
A  modification  of  the  position  of  the  wall  on  Hog's  Back  and  Holmes  Rock  may 
result  from  a  new  examination. 

Respectfully  submitted  : 

JOHN  NEWTON, 
Lieut.  Col.  Engineers  and  Brevet  Major  General  U.  S.A. 
Brevet  Major  General  A.  A.  Humphreys, 

Chief  of  Eng  ineers  U.  S.  Army,  Washington,  D.  C. 


Tabic  showing  quantities  of  rod;  to  be  blasted  and  remored  from  certain  localities,  fcc. 

Depth  increased  to  26  feet  mean  low  water. 


Locality. 


Pot  Rock  

Frying  Pan  

Ways'  Reef  and  Shelldrake  

Heel  Tap  

Negro  Head  and  Middle  Channel  

Rock  off  Negro  Point  

Scaly  Rock  

Hallet's  Point  

Hen  and  Chicken,  Flood  Uoek.  Gridiron, 
Negro  Head,  and  Middle  Channel  


152 
180 
101 
285 

:i,  248 
21 
121 

1,391) 

6,  808 


064 
240 
707  i 
896 
736 
111 
847  | 
790 


47,  G.-iU 


41, 
48, 
27, 
74, 
893, 
5- 
33, 


850 
450 
850 
250 
200  1 
550  ! 
350 
950 


1,914,000 


387 
443 
253 
685 

8, 120 
51 
303 

3,  399 

17,  296 


320  t 
372  I 
212 
569 

6,  821 
43 
254 

2,  937 

14,  296 


12, 125 

12,475 
6,  200 

23,000 
276,  800 
1,400 
8,  500  ! 

73,800 


33,  500 
51,  675 
44,  200 
53,  000 
1,  456,  400 
7,  700 
49,  300 
841,  030 


426,800  4,272,000 


SURVEY  AT  HELL  GATE,  EAST  RIVER. 


11 


Table  showing  the  quantities  of  rocl;,  8fe. — Continued. 


Locality. 


Pot  Rock  

Frying  Pan  

Wav's  Reef  and  ShelWrake  

Heel  Tap  

Negro  Head  and  Middle  Channel  

Rock  off  Negro  Point*  

Scaly  Rockt  

Hallet'a  Point  , 

Hen  and  Chicken,  Flood  Rock,  Gridiron, 
Negro  Head,  and  Middle  Channel  


Depth  increased  to  24  feet  mean  low  water. 

•£ 

5 

1 

1  & 

I* 

i 

w  u 
o  S 

V 

o 
< 

2 

5« 

o 

rjl 

'Z 

s 

1 

.a 
St 

u  - 

152 
120 
101 
*  114 

2,  240 

1,0G4 
840 
707 
800 
15, 080 

40,  000 
30,  000 

27,  850 

28,  200 
724,  000 

368 
280 
253 
264 
6,  320 

10,  000 
9,  000 
6,  200 
9,  000 
196,  000 

320 
252 
212 
240 
4,704 

10,971 
30,  000 
31,800 
29,  500 
994,  000 



1,  399 

9,  790 

369,  650 

3,  399 

73,  000 

2,  937 

775,  330 

5,  800 

40,  GOO 

1,595,  200 

14, 500 

322,  000 

12,180 

3,  515,  600 

*  To  obtain  a  depth  of  20  feet  at  mean  low  water. 
tTo  cut  off  its  projection  into  the  channel. 


Estimate. 


Designation  of  work  and  materials 


FIRST  PROJECT— SIX   PEARS  OPERATIONS, 


5,  at  $41  75  

at  $45  80  

.,  at  $41  75  

Bt,  at  §1  

,  at  $1  

<,  viz..  Negro  Head,  and 
tin1  width  of  tlic  middle 

at  $45  -80  

s  at  $41  To  


To  secure  a  depth  To  secure  a  depth 
of  26  ft.  at  mean!  of  25  ft.  at  mean 
low  water.  low  water. 


8103,402  20 

194,590  75 


1,080,405  00 


1  48,758  40 
208,406  on 


Blasting-  and  removing  rock,  viz :  Pot  Rock,  Frying-pan, 
Way's  Reef,  Shelldrake,  Heel  Tap,  rock  off  Negro 
Point,  Scaly  Pock,  and  Hallet's  Point— 

2,259  50-poun<J  charges,  at  §45  SO  

4,601  150-pound  charge 
2,028  50-pound  charges, 
4,289  150-pound  charges 
Removing  1,080,405  cubic  fe 
Removing  934,601  cubic  feet 
Blasting  and  removing  rocl 
deepening  and  increasing 
channel — 

3,248  50-pound  charges, 
4,872  150-pound  charge- 

2,240  50-pound  charges,  at  §45  80  

4,080  150-pound  charge*,  at  $41  75  

Removing  1,456,400  cubic  feet,  at  $1  

Removing  994,000  cubic  feet,  at  $1  

Sea-wall  of  cut-stone  along  the  Hen  and  Chicken, 
Flood  Rock,  and  the  Gridiron,  including  preparing  bed 
for  foundations,  and  breakwater  of  wood  to  protect 
the  workmen  from  the  force  of  the  currents,  1,140 
feet  long,  10  feet  wide,  20  to  28  feet  high,  top  four 

feet  above  high  water,  10,000  cubic  yards,  at  §80  

Rubble  sea-wall,  finished  on  top  with  large  blocks  laid 
by  hand,  750  feet  long,  along  the  twelve-feet  curve  of 
Hog's  Back  and  Holmes's  Rock,  viz: 

10, 056.  0  cubic  yards  of  dry  rubble,  at  $4  50   45, 252  00 

3, 052. 5  cubic  yards  of  stone-masonry,  at  §24  |  73, 260  00 

Rubble  sea-wall,  as  before,  along  the  seventcen-feet  ' 
curve  of  Great  and  Little  Mill  rocks,  next  the  middle 
channel,  450  feet  long,  viz  : 

15, 660.  0  cubic  yards  of  dry  rubble,  at  §1  50  1  70,  470  00 

1 , 831 .  5  cubic  yards  of  stone-masonry,  at  §24  '  43,  956  I M 1 


1,456,400  00 


$92,882  40 
179,065  75 

934,601  00 


102,590  00 
169,340  00 

994,000  00 


800,000  (io 


45,252  00 
73,260  00 


711,470  on 
43,956  oo 


12 


SURVEY  AT  HELL  GATE,  EAST  RIVER. 
Estimate — Continued. 


Description  of  work  or  materials. 


I  I 

To  secure  a  depth  To  secure  a  depth 

of  26  ft.  at  mean    of  24  ft.  at  mean 

low  water.  low  water. 


Rubble  dike,  as  above,  closing  the  channel  between 
Bread  and  Cheese  and  the  end  of  Blackwell's  island, 
250  feet  long,  viz : 

2, 250.  0  cubic  yards  of  dry  rubble,  at  $4  50  

3 ,  017.  5  cubic  yards  of  stone-masonry,  at  .$24  1 

Rubble  sea-wall,  as  above,  along  the  twelve-feet  curve  ! 
of  Bread  and  Cheese,  210  feet  long,  viz: 

2,  952.  6  cubic  yards  of  dry  rubble,  at  84  50  

854.  7  cubic  yards  of  stone-masonry,  at  $24   

Rubble  sea-wall,  as  above,  along  the  twelve-feet  curve  '( 
of  Rylander's  reef,  210  feet  long,  viz  : 

3, 729.  0  cubic  yards  of  dry  rubble,  at  $4  50  

854.  7  cubic  yards  of  stone-masonry,  at  $24  


Machinery. 

One  iron  floating  current-breaker,  160  feet  long  

One  iron  floating  current-breaker.  100  feet  long  

Two  floating  derricks  

One  scow,  with  50  feet  mast  and  hoisting  gear  

Six  scows,  60  feet  long  

Two  scows,  each  60  feet  long,  with  valve  bottoms  

Sixteen  scows,  each  30  feet  long  

Six  small  boats    

Two  drilling  platforms  

Anchors,  chains,  buoys,  hawsers,  tow-lines,  fasts,  falls, 
and  lashings  

Repairs  oL  machinery,  due  to  wear  and  tear  and  collis- 
ions with  vessels,  loss  of  anchors  and  chains  and 
replacement  of  rope,  for  six  years'  service, being  about 
sixty  per  cent,  of  the  prime  cost  


Contingent  and  general 


Two  clerks,  at  $130  each. 


. . .  $18, 120  per  annum. 


Two  draughtsmen,  at  $130  each..  3, 120 

One  messenger,  at  $60   720 

Rent  of  office   1,500 

Expenses  of  office   1,200 

Two  chief  divers,  at  $380  each  ...  7,  600  ten  mouths,  j 

One  master  mason,  at  $150   1 ,  800 

One  overseer  of  laborers,  at  $120.  1,  440  " 

One  master  blacksmith,  at  $120  . .  1 , 440 

One  master  carpenter,  at  $120   1 ,  440 

One  rigger,  at  $100    1, 200 

One  storekeeper,  at  $1 20   1 ,  440 

Four  sub-overseers,  at  $60  each. .  2,880  " 

Six  night  watchmen,  at  $50  eacli.  3,600 

Forty  laborers   18,960 

Three  tugs,  at  $50  per  day   33,  000 

r-i,  460 — Then  6  yrs. 

Lease  of  ground  fur  storehouses  

Construction  of  wharf  and  repairs  

Wharf  derrick  

Construction  of  storehouses,  mag;;/.ines,  &c  

Blasting  and  removing  certain  small  rocks,  viz:  Bald-  I 
headed  Billy,  Black  well's  Rock,  rocks  near  Wool-  j 
sey's  bath-house  j 

Total  for  improvement  by  first  project  


$9, 990  00 
24,420  00 


13,286  70 
20,  512  80 


16,780  50 
20.512  80 


$150,000  00 
110,000  00 
30.000  00 
5,000  00 
18,000  00 
7,000  00 
35,200  00 
1,800  00 
80,000  00 

37,000  00 


2*1,400  00 


506,760  00 
25, 000  00 
42,000  00 
3,500  00 
15,000  00 


50,000  00 


89,990  CO 
24,420  00 


13,286  70 
20,512  80 


16,780  50 
20,512  80 


$150, 000  00 
110,000  00 
30,000  00 
5,000  00 
18,000  00 
7,000  00 
35,200  00 
1,800  00 
80,000  00 

37,000  00 


281,400  00 


506,760  00 
25, 000  00 
42, 000  00 
3,500  00 
15,000  00 


50,000  00 


5,723,129  15 


»,  008,  579  95 


SURVEY  AT  HELL  GATE,  EAST  RIVER.  13 


Estimate — Continued. 


Designation  of  work  or  materials. 

To  secure  a  depth 
of  26  ft.  at  moan 
low  water. 

To  secure  a  depth 
of  24  ft.  at  mean 
low  water. 

SECOND  PROJECT — TEN  YEARS.'  OPERATIONS. 

Add  to  amount  of  first  project,  the  cost  of  removing 
Negro  Head,  Flood  Rock,  Hen  and  Chicken,  and  the 
Gridiron,  increased  by  extra  repairs  and  replacement 
of  machinery  and  increased  contingent  services  for 
ten  instead  of  six  years,  and  diminished  by  cost  of 
removing  Negro  Head  and  improving  the  middle  chan- 
nel, and  of  cut  stone  sea-wall  designed  for  the  Grid- 

$5,723,129  15 
2,969,516  00 

$5, 008, 579  95 
2,729,395  00 

8,692,645  15 

7,737,974  95 

THIRD  PROJECT— FOUR  YEARS'  OPERATIONS. 

Omitting  all  improvement  of  the  middle  channel,  with 
corresponding  diminution  of  cost,  and  decreased  wear 
and  tear  of  machinery,  and  of  contingent  services, 
viz. :  amount  to  be  deducted  from  the  cost  of  first 
project  

2,876,324  40 
2, 846, 804  75 

» 

2,  333, 650  00 
2,674,929  95 

JOHN  NEWTON, 
Lieut.  Col.  Engineers,  Bit.  Maj.  Gen.  U.  S.  A. 


lEx  Safaris 


SEYMOUR  DURST 


When  you  leave,  please  leave  this  hook 

Because  it  has  heen  said 
"£ver'thing  comes  t'  him  who  waits 

Except  a  loaned  hook." 


6  o  y  H  \ 


Avery  Architectural  and  Fine  Arts  Library 
Gift  of  Seymour  B.  Durst  Old  York  Library 


